EMGs
Does a dirty (abnormal) EMG mean I have ALS?
EMG, properly done, is the gold standard test for ALS. But an abnormal EMG can indicate hundreds of other, non-fatal, diseases. So listen to your doctor.
My EMG was done “too early”
EMGs cannot be done too early. 70% of a nerves fibers die before you feel weakness. An EMG will detect that process long before you can feel it.
Here is a simplified summary:
1. ALS causes nerves to die.
2. EMG detects effects of nerves dying.
3. For ALS, muscles get weak and atrophy when they lose their nerves (no pun intended).
4. Therefore a weak or atrophied muscle due to ALS will absolutely, positively show up on EMG. Clean EMG = No ALS and a clean EMG plus a normal clinical exam = no Motor Neuron Disease at all